Stephen Miller will write President Trump’s speech on Islam and “radical ideology,” set to be delivered when Trump visits Saudi Arabia later this month on his first foreign trip.

“The speech is intended to unite the broader Muslim world against common enemies of all civilization and to demonstrate America’s commitment to our Muslim partners,” national security adviser H.R. McMaster said, according to ABC News.

Representatives from more than 50 Muslim countries will be in attendance during the address. Saudi Arabia will be the president’s last stop on a trip that will include touchdowns in Israel and Vatican City.

Miller, who is the White House’s domestic policy director, has figured as a key speechwriter for Trump, authoring many of his speeches on the campaign stump as well as the inaugural address the president delivered in January.

A former aide to now-Attorney General Jeff Sessions, and a sometime protege of chief strategist Steve Bannon, Miller is identified with the administration’s nationalist-populist wing.